Saving Dal Lake, naturally

Dal Lake in Srinagar will now have a ring of natural defence against polluting elements.

The Jammu & Kashmir government is planning a 3-km-long and a 150-metre-wide reed zone on the shores of the shrinking lake to treat the sewage coming from the catchment areas before the water gets into the lake.

The reed belt will cover the 21 square km lake's northern shore. Reed is tall slender grass that grows in marshes and shallow water.

Apart from the reed belt, the Lakes And Water Development Authority (LAWDA) is planning to create artificial marshes and wetlands at the opening of the sewage outlets. The buffer zone will act as a natural bio-filter and act on substances like phosphorus and nitrogen before they pass into the lake.

“The weeds and reed in the marshes and the buffer zone will act on the nutrients and (absorb) them for their own growth, (thereby) cleaning the water before it goes to the lake,” said Irfan Yaseen, vice-chairman, LAWDA.

The step has been taken as part of the Rs 25-crore project to prevent the sewage from getting into the lake.

“Half the land acquisition has been done. Some land is private property (and) we are trying to acquire that as well. But we should start the project very soon,” he added.

According to a report prepared by the University of Roorkee’s Alternate Hydro Energy Centre, the sewage brings with it nitrogen and phosphorus, which have changed the physical and chemical properties of the Dal waters.

There are tributaries, sewage drains and diffuse runoffs from catchment areas that bring these nutrients to the lake, the report says.

“The water quality has shown improvement as the sewage treatment plants are working very well but there are many entry points where biofiltering is the only way out,” Yaseen said.